Tena koe Yu
?is.null
HTH ...
Peter Alspach
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Yuan Jian
> Sent: Monday, 26 July 2010 5:05 p.m.
> To: r-help at r-project.org
> Subject: [R] NULL
>
> hi,
> I have a simple problem.
>
> how can I test whether a variable is NULL?
>
> a = NULL
> if (a == NULL){
> ...
> }
> it seems not work
>
> thanks
>
> YU
>
>
>
>
>
>
> [[alternative HTML version deleted]]
>
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